Barack Obama’s security network reportedly warned authorities of “pre-9/11” levels of terrorist communication interception before the closure of 22 U.S. embassies across the Middle East region, reported The Guardian.

On Saturday, Obama’s security team held a meeting regarding an undisclosed but substantial threat to Western institutions in the Middle East, prompting the embassy closings, according to The Guardian.

Yemen is a country of particular concern, with security around the U.S. Embassy tightened to include 12 tanks within 500 meters of the building, reported CNN. Other Western nations have also shuttered their embassies in Sanaa, Yemen’s capital. Britain said its embassy would remain closed until Thursday, which marks the Muslim holiday of Eid, signaling the end of the month of Ramadan.